汽车尾气是城市空气污染的重要来源。Qìchē wěiqì shì chéngshì kōngqì wūrǎn de zhòngyào láiyuán.Car exhaust fumes are a major source of urban air pollution.
早上公交车站尾气很重,我赶紧捂住了鼻子。Zǎoshang gōngjiāochē zhàn wěiqì hěn zhòng, wǒ gǎnjǐn wǔzhùle bízi.In the morning the exhaust was heavy at the bus stop, so I quickly covered my nose.
多骑自行车可以减少尾气排放。Duō qí zìxíngchē kěyǐ jiǎnshǎo wěiqì páifàng.Riding a bicycle more often can reduce exhaust emissions.